May 31, 2006

Chickenpox party, anyone?

It’s a good thing the Food and Drug Administration recently licensed a new vaccine to reduce the risk of shingles in older Americans. The rate of shingles is on the rise, and some researchers believe it’s because school-aged children are vaccinated against the chickenpox, a related but less serious virus.

What happens is this: After a child has the chickenpox, the virus becomes dormant and can reactivate later in adulthood as shingles. Both are caused by the same varicella-zoster virus.

It’s thought that shingles generally doesn’t reactivate because it’s suppressed by an invisible "booster" that occurs whenever an adult is exposed to a child infected with chickenpox. In other words, once we’ve had chickenpox, we have a natural booster against shingles throughout life.

If the wild chickenpox virus isn’t circulating in the environment, we won’t get the natural booster. That means adults will be at greater risk of contracting shingles, which results in three times as many hospitalizations and five times as many deaths as chickenpox.

Essentially, we’re now stuck in a vicious cycle, having to buy a shingles vaccine to control a shingles epidemic started by a chickenpox vaccine, which the state health board said didn’t need to be mandatory in the first place.

Meanwhile, it’s extremely difficult to get adults in for vaccinations. And chickenpox has never been a major public health threat. An itchy, blistering inconvenience, maybe, but certainly something past generations were able to live with. There’s something to be said for natural immunity.

Old-fashioned chickenpox parties aren't very well publicized these days and for good reason. The unusual gatherings, held to intentionally infect a healthy child with the wild version of the varicella virus, can sound both cruel and reckless, especially because a vaccine is available.

But there's a method to this South Park-like parental madness. Not so long ago, most people contracted chickenpox as children and gained lifelong protection from the disease.

It was a miserable rite of passage, and the itchy, blistering sores of chickenpox meant missed school and work. But in past generations, less than 1 percent of children needed to be hospitalized, and it was rarely fatal. Chickenpox was not a major public health threat.

Pharmaceutical companies pushed a vaccine anyway. It became available in 1995, and though the state health board advised against a mandatory vaccine, controlled doses of the live virus are now required for admission to Illinois schools and many day-care facilities.

While more kids used to die each year from bike accidents than chickenpox, the vaccine reduced the death rate and cases of flesh-eating disease in young children. Chickenpox-related hospitalizations and spending have dramatically declined. And the 10 to 30 percent who are vaxed but get the chickenpox anyway have milder symptoms.

Yet the vaccine's benefits for children may have an unintended cost: a shift of the disease to older age, when it is more severe, and a potential increase of a related, more serious disease--shingles--among adults and the elderly.

After a child has had chickenpox, the virus becomes dormant and can reactivate later in adulthood as shingles. Both are caused by the same varicella-zoster virus. It's believed that shingles reactivation is suppressed naturally through an invisible "booster" that occurs whenever an adult crosses paths with a child who is infected with chickenpox.

The concern is that if the wild chickenpox virus isn't circulating, older people won't be exposed to the natural booster. They'll be at greater risk of contracting shingles, which results in three times as many hospitalizations and five times as many deaths as chickenpox.

British infectious-disease modelers estimate that shingles might increase 30 to 50 percent from vaccination. And research published in the International Journal of Toxicology shows higher rates of shingles in Americans since the government recommended a national immunization program in 1995.

In economic terms, a relatively small increase in the cases of shingles "could potentially offset the medical cost savings associated with reductions in 4 million varicella cases and associated morbidity for many years," according to the analysis in the journal by researcher Gary Goldman.

"It's the first time whereby a `shingles vaccination' is now needed to offset a `chickenpox vaccination,' resulting in a continuous treatment cycle," Goldman said.

Using a shingles vaccine to control a shingles epidemic started by a chickenpox vaccine makes as much sense as attending a chickenpox party. But while it would be a cash cow for drug companies, it would likely fail from a public health perspective because adult vaccination programs are notoriously unsuccessful.

Unfortunately, chickenpox parties aren't the answer, either. I'm not sure I could sit back and watch my son chew a piece of gum that had already been moistened by an infected child. It's irresponsible to make your child sick when a vaccine is available, even if you believe it's better for him in the long run. Pneumonia, encephalitis and bacterial infections are all possible complications.)

But more important, the pox play dates won't work in the long run. Because so many children are receiving the vaccine, there are fewer around to "naturally" expose unvaccinated children.

If my child did manage to get infected at a party, the one-time exposure wouldn't likely provide lifelong protection as in the past, because he needs periodic encounters with other infected children throughout life to stimulate the invisible boost to the immune system.

If Goldman is right, this is the same reason that the vaccine's effectiveness will wear off, too. We don't yet know what happens to those who receive a vaccine but are not exposed to naturally occurring chickenpox.

But Goldman has found that the effectiveness of the chickenpox vaccine also is dependent on natural boosting. As the wild chickenpox virus declines, he said, so does the effectiveness of the vaccine.

Comments

There's a LOT to be said for natural immunity. Thus far we've opted to skip all shots for our 17 month old and haven't had a single regret thus far. Those interested in the topic should pick up Dr. Tenpenny's DVDs on the subject of vaccinations - very insightful.

I would like to be in touch with a group of parents and or start a group of parents that have read a great deal on vaccinations and understand the risk benefit equation as well as the alternative methods and more thoughtful ways to selectively vaccinate our children. I would also like more comments on the possibilities of organizing chiken pox parties in a way that is smart, well planned and people are willing to meet in the future for natural boosters. Any commnets out there?
Regards to all parents who have or are doing their long and complex homework in the world of vaccinations.
Leah

What these articles fail to mention is that the immunity from having chickenpox naturally can wear off over time, too! I had chickenpox when I was 10 years old (I've got the pox scars to prove it!) but at age 26 found out that I was no longer immune. My immunity had somehow worn off. I always thought it would be better for my kids to have chickenpox naturally because I assumed they would then gain lifelong immunity, unlike the vaccine which may wear off after 10 years (or more, or less). I guess we will all be getting vaccinated after all.